/Engine/Source/Developer/SourceControl/Public/SourceControlOperations.h
If no target directory was given to download the files too then the command will keep the files in memory which can be accessed via this method. If the file failed to download then a nullFSharedBufferwill be returned.
[FSharedBuffer](API\Runtime\Core\Memory\FSharedBuffer) GetFileData ( const FStringView & Filename )